Apparatus for inspecting moving transparent objects



Aug. 3, 1948. H. H. MARSHALL 2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS Filed Aug. 29, 19444 Sheets-Sheet l INVENTOR ATTORN EYJ Aug. 3, 1948. H. H. MARSHALL2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS Filed. Aug. 29, 19444 Sheets-Sheet 2 H T NVENTOR Aug. 3, 1948. H. H. MARSHALL 2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS 4 INVENTOR 5. g ORNE.5

Aug. 3, 1948. H. H. MARSHALL APPARATUS FOR INSPECTING MOVING TRANSPARENTOBJECTS Filed Aug. 29, 1944 4 Sheets-Sheet 4 INVENTOR Patented Aug. 3,1948 APPARATUS FOR msPnc'rrNG MovrNo TRANSPARENT onmo'rs Henry HallMarshall, Garden City, N. Y., assignor, by mcsne assignments to PabstBrewing Company, Chicago, Ill., a corporation of Dela- ApplicationAugust 29, 1944, Serial No. 551,759

' 8 Claims. (oi. 88-14) 1 This invention relates to inspection devicesfor light transmitting articles, and more particularly to visualinspection devices in' which light from a source is directed throughcontainers or bottles and their contents which are transparent ortranslucent, whereby imperfections are indicated by shadow orinterruption light;

In bottle handling operations,.it is customary to pass the bottles inlinear succession on a conveyor or the like, for inspection by anobserver, but after they pass the observer, a foreign particle in one ofthe bottles is diflicult to retain in view because the bottles pass outof focus and the light transmission and refraction by the contents varyto a degree making inspection uncertain.

It is the principal object of this invention to provide bottle.inspection apparatus in which the bottles pass from the conveyor incontinuous contact along an arcuate path, whose center of curvature isat the observer's station, so that each bottle remains in focus duringits entire course along the arcuate path and the light transmission andrefraction therethrough remain constant, thus enabling accurate andcertain inspection. 4 In their course along thearcuate inspection paththe bottles mesh with apertures in an opaque screen which is accordinglyadvanced by and with the bottles and confines the light to the contentsof the bottles, which are thus not only uniformly illuminated, but arealso masked against glare. After leaving the arcuate inspection path,the bottles are returned to the conveyor in contacting relation and insynchronism with the oncoming bottles being fed by the conveyor, so thatno delay in production is necessitated by the inspection.

Other objects and features of novelty will be apparent as the followingdescription proceeds, with reference toothe accompanying drawings, inwhich:

Figure 1 is a horizontal section through the inspection device accordingto the preferred embodiment of the present invention, as taken along theline i--l of Figure 2;

Figure 2 is a vertical section taken along the line 2-2 of Figure 1;

Figure 3 is a detail elevation of a portion of the shield; I

Figure 4 is arvertical section taken along the line 4-4 of Figure 3; A

Figure 5 is a vertical section taken along the line 5-5 of Figure 1,showing the screen supporting reel;

Figure 6 is a section taken along the line 66 of Figure 5, and

of the transmitted of Figure 6.

According to the present invention, a shield of light resisting materialis provided with apertures shaped to-receive the articles or containersto be inspected, the shield being flexible or articulated to form anendless belt enclosing the light source. The articles are fed to theinspection device by a conventional conveyor, and are deflectedtherefrom in contact along an arcuate path on an inspection table, thecenter of curvature of the inspection path being at the observer'sposition, so that the bottles are always the same distance from, theobserver. As the articles are deflected, they enter the apertures on thescreen belt, and carry the belt along with them.- Thus the articlesremain in focus while inspected, glare being eliminated by the screen. Adelivery guide directs the articles as they move off the table so thatthey pass ,out of the apertures and back onto the conveyor.

The inspection device shown in the drawings comprises a frame F whichsupports an inspection table T, to which the bottles 13 are fed by aconveyor 0. The screen S is provided with apertures A which receive thebottles B which move the screen with them as they pass along the table Tin front of the lamp bank or other light source L. The screen isflexible or articulated to form an endless belt, which passes over oraround vertical spools or reels R, and along a curved path whose centerof curvature is at the observers position 0. A feed deflector M earnsthe bottles B off the conveyor C onto the table T and into the aperturesA for travel in contact along the curved path whose center is at O, anda delivery guide D directs the bottles as they move ofi of; the table Tand out of the apertures A and back onto the conveyor C.

As shown in Figures 3 and 4, the screen S is constructed of opaquematerial, preferably flexible, the form shown being asbestos fiberfabric impregnated with synthetic rubber. Vertical supporting andreinforcing rods H) are provided at equal intervals the screen beingsecured or clamped between the rods Ill and retaining strips l2 byscrews l 4 passing therethrough.

A relatively wide band ii of the screen material is provided at the top,the lower portion of this band between each pair of adjacent rods I 0being cut away as at IE to conform to the bottle neck and form the topof the aperture A. Above the cut away portion 46, and between each pairof adjacent rods Hi, the band I5 is provided with a reinforcing strip llof the screen material which its machine stitched or otherwise securedin posi- The rods I 0 form the sides of the apertures A. and the bottomsof these apertures are formed by the top of a relatively narrow band (8of the similar reinforcing strip a under each aperture.

Each rod "has secured to the bottom thereof a bracket 22, which providesa journal for a supporting roller 24. At the top of each rod ID abracket 25 provides a Journal for a guide roller 2.

As shown in Figure 2, the lower or supporting rollers 24 ride on a track30 having guide flanges on each side thereof, and the upper or guiderollers 26 pass between upper guide flanges Ii and 32. The track 3|! ismounted on the frame F below and in back of the inspection table T,which is supported from the frame F by suitable brackets or posts 33.The guides 3| and 32 are secured to a top plate 3|.

The guides 3i and 32 and the track 30 are curved about inspection centerand track 30 extends between the front spools or reels RI and R2 in backof the inspection table T. It should be noted that this curved path iselongated, being ofgreater extent than the corresponding part of y thestraight conveyor C, thereby permitting not only inspection at aconstant distance from center 0 but allowing a substantial inspectiontime.

As shown in Figure 5, each reel R comprises a shaft 35 journaled inbearings I8 and having an upper flange 31 adapted to be engaged at itsperiphery by the guide rollers 28 at the upper ends of the rods II. Theshaft 36 also carries a lower flange 38 which has a peripheral shoulderadapted to receive the supporting rollers 24 at the lower ends of therods ill.

The reels R3 and R4 at the back of the inspection device have theirbearings adjustably mounted so as to take up slack in the endless beltformed by the screen 8 so that as the rollers 24 and 26 engage theirflanges, the screen material therebetween flattens or straightens out asshown in Figure 1.

The adjustable mounting for the bearings of the reels is shown inFigures 6 and 7. The hearing 36 is mounted in a cage ll which isslidable along a guide 42. A screw 43 extending longitudinally of theguide 42 threadedly engages the cage 40, and moves the cage along theguide, a coil spring 44 being provided to urge the cage outwardly.

As shown in Figure 1, straight guides otherwise similar to the track 30and flanges SI and I! are provided to guide the remaining bights of theendless belt screen S. A guide 46 extends from dellvery reel R2 to therear reel RI, 9. guide 41 extends between the real-reels R3 and R4, anda uide 48 extends from the rear reel R4 to the feed reel RI. Theseguides are adjustably mounted on the frame F by bolts entering slots 0in the frame. g I

The light source L comprises a lamp bank or panel 50 extendingvertically from the frame F. The panel Bil supports sockets ii for lampbulbs 52 extending toward the bottles, the rear of the panel 50 havingboxes 53 to enclose suitable wiring. Between the bulbs 52 and thebottles a ground glass panel 55 is provided to diffuse the light. Asshown in Figure 2, the panel it rests in a groove 56 provided on theframe F, and is removably secured in position by a bolt and a wing nut51 on the top plate 34.

As shown in Figure 1, the sides of the lamp bank L are enclosed by lightshields extending forward from the panel 50, beyond the ground glasspanel 55, and extending inwardly to the shafts 35 of the reels RI andR2. Thus the light is restricted to the extent of the inspection tableT. In front of the inspection table I, as shown 4 in Figure 2, a splashshield n is provided, to cover the part of the conveyor 0 between thedeflector M and the guide D. In front of the conveyor C an inspectionwindow 8| of clear glass is provided.

Above the bottles on the inspection table T a guard plate II is suitablysupported from the top plate 34, leaving an open space between the guardplate 8| and the window I for the withdrawal or rejected bottles.

In operation, the articles to be inspected, such as bottles, are fedinto the inspection device by the conveyor C and engage the deflector Mwhich cams them laterally oil. the conveyor C onto the inspection tableT. This camming action causes the leading bottle to enter the aperture Aof the screen 8, at the time when the screen is leaving the front feedreel RI and is moving onto the curved guide track 30. The width of theaperture A between adjacent rods I0 is less than the width of thebottle, so that the bottle cannot pass through the aperture, but entersand snugly engages it.

Although the leading bottle by this time has left the conveyor C, theoncoming bottles are pushed on by those following, and as the oncomingbottles enter the apertures A, the screen 8 is moved in the samedirection by the oncoming bottles. The track 30 defines the path of thescreen which in turn defines the path of the bottles in the apertures,along the inspection table T.

The lamp bank or light source L having been turned on, the light shinesthrough the ground glass and through the bottles in the apertures. Theopaque, closely fitting screen 8 obstructs the light outside thebottles, so that only the light passing through the apertures A mayreach the inspector. Thus the bottles and their interiors are adequatelyilluminated for inspection purposes, while glare and excess light areeliminated. At the same time, the bottles are progressed through themachine so that the inspection operation may be rapidly accomplished ata constant distance from 0, and so that the inspector may view eachbottle under the same conditions throughout its curved path, withoutdistortion, variation in light intensity, or glare.

As the bottles reach the delivery front reel R2, they engage thedelivery guide D which guides them back onto the conveyor C. Thefollowing bottles act to propel the leading bottles throughout theircourse onto and oil of the table T, while the screen 8 passes around thereel R2 to continue its circuit.

Although a preferred embodiment of the invention has been describedherein, it is to be understood that the invention is not limitedthereby, but is susceptible of changes in form and detail within thescope of the appended claims.

I claim:-

1. Inspection device for light transmitting articles, comprising incombination, a source of light, a conveyor for feeding the articles inlinear succession in contact with each other in a path adjacent said'light source, a shield of light resisting material having aperturesshaped to receive said articles, whereby light from said source istransmitted through said articles, and glare from said light sourceoutside of said articles is obstructed, means for supporting said shieldfor lateral movement, means directing articles from said conveyor intothe apertures in said shield, whereby said shield is moved by thearticles being fed by said conveyor and entering said apertures,

and guiding means cooperating with said shield and conveyor for movingthe articles along an arcuate path having a. center of curvature lyingon the opposite side of the arcuate path from the light source.

2. Inspection device for light transmitting articles, comprising incombination, a source of light, a conveyor for feeding the articles inlinear succession before said source of light, a shield of lightresisting material having apertures shaped to receive said articles,means for mounting said shield vertically for movement in a horizontalpath between said conveyor and said source of light, an inspection tablebetween said conveyor and said shield, means for deflecting saidarticles oil? of said conveyor onto said table and into said apertures,and means for guiding said shield in an arcuate path between saidconveyor and said light source.

3. Inspection device for light transmitting articles, comprising incombination, a source of light, a conveyor for feeding said articles inlinear succession before said light source, a pair of reels journaled onvertical axes on respective sides of said light source, an endless beltof light intercepting material mounted on said reels and havingapertures'shaped to receive said articles, an inspection table betweensaid conveyor and said belt, means for deflecting said articles fromsaid conveyor onto said table and into said apertures as the front bightof said belt leaves the feeding reel, and means for guiding saidarticles ofi said table and onto said conveyor when they leave saidapertures as said front bight passes onto the receiving reel,

1. Inspection device for light transmitting articles, comprising incombination, a source of light, a conveyor for feeding the articles inrectilinear succession and contacting relation, a vertical shield oflight intercepting material having apertures shaped to receive saidarticles and vertical supporting rods between said apertures, aninspection table in front of said light source and level with saidconveyor, said shield comprising an endless-belt having an articlereceiving bight msing in front of said light source and along saidinspection table, and a return bight passing in back of said lightsource, a deflector for camming each article in succession of! of saidconveyor and onto said table into engagement with the rod of said shieldahead thereof, whereby the following articles still on said conveyorpush the leaving article onto said table and into its aperture andpropel said front bight across said table, and a delivery guide at thedelivery end of said front bight for directing said articles leavingsaid table back onto said conveyor.

5. Inspection device for light transmitting articles. comprising incombination, a source of light, a conveyor for feeding the articles inrectilinear succession, a pair of reels having vertical shafts mountedat the respective sides of said source of light. an endless belt carriedby said reels and having apertures shaped to receive said articles,vertical supporting rods secured to said belt between said apertures. aninspection table in front of said light source between said reels andlevel with said conveyor, a curved guide extending between said reelsand located below said inspection table and in front 7 of said lightsource for deflecting the front bisht of said belt away from saidconveyor and toward said light source, means for guiding the returnbight of said belt from one reel to the other in back of said lightsource, a guide for directing each article in succession of! of saidconveyor onto said table and into engagement with an aperture of saidshield, and a delivery guide cooperating with said belt and conveyor fordirecting said articles off of said table and back onto said conveyor.

6. In a device for inspecting light transmitting articles from aninspection position, the combination of a light emitting panel ofconsiderable area, a pair of reels having substantially parallel shaftsmounted one on each side of said light panel. an endless belt of lightintercepting material mounted on said reels and passing between saidlight panel and said inspection position, said belt having adjacentlight transmitting apertures shaped to receive said articles, meanscooperating with said reels to cause said belt to form an arcuatearticle receiving pass a lurality of adjacent apertures in length infront of said light panel and a return pass in back of said light panel,said arcuate pass having a center of curvature lying substantially atsaid observation position, and means directing articles to said arcuatepass and into said aperture. 1

7. In a device for inspecting light transmitting bottles from aninspection position, the combination of a light emitting panel ofconsiderable area. a vertical shield of light intercepting materialinterposed between said light panel and said inspection position, saidshield having apertures adapted to receive said bottles and verticalsupporting rods secured to said shield between said apertures,supporting rollers Journaled at the bottoms of said supporting rods, andmeans cooperating with said shield and supporting rollers for guidingsaid shield along an arcuate path a plurality of adjacent articlereceiving apertures in length and having a center of curvature lyingsubstantially at said inspection position.

8. In a device for inspecting light transmitting articles from aninspection position, the combination of a light emitting panel ofconsiderable area, a shield of light intercepting material in-- terposedbetween said light panel and said inspection position, said shieldcomprising an endless belt and having adjacent light transmittingapertures formed therein within which said articles are adapted to bedeceived, vertical supporting rods secured to said shield between saidapertures, rollers journalled on said rods, means cooperating with saidrollers for guiding said belt to form an arcuate article receivingportion in front of said light panel, a return portion in back of saidlight panel, said arouate belt portion including a plurality'oi'vadjacent article receiving apertures in its length and having a centerof curvature lying substantially at said inspection position, and meansdirecting light transmitting articles to one end of said arcuate beltportion and into said apertures.

HENRY HALL EiARSI-IAIL.

REFERENCES CITED The following references are of record in the file ofthis patent: 4

UNITED STATES PATENTS 2,368,350 Ellison Jan.- 80, 1945

